1. Field of the Invention
This invention has relation to the use of pneumatic particulate material conveyors used to convey grain from and to storage bins, silos, grain trucks, railroad grain cars, and the like. Specifically, it relates to a pick-up assembly for air entraining piles of such materials resting on generally horizontal surfaces and in cleaning the residue of such particulate materials from such bins, silos, trucks, cars and the like.
2. Description of the Prior Art
It is known to convey grain and other particulate material by pneumatic means. For example, Neuero Corporation sells ship unloaders; seed handling pneumatic grain conveyors Models 660, 8110D and 210; and others. Vana Industries Ltd. sells CONVEYAIR brand grain vacuums Models 1955, 2955, 3005, 4005 and others. Christianson Systems, Inc. sells HANDLAIR brand pneumatic conveyors Models 560, 660 and others.
A major advantage of such pneumatic conveying system is to move grain or other particulate material without stirring up dust as is the case when grain augers and the like are used.
In accordance with the prior pneumatic conveying art, elongated solid conduits having open ends are attached to flexible hoses to pick up and convey the particulate materials. These conduits customarily included a bend therein to allow an operator to support a conduit from shoulder straps so as to carry it and whatever forward pick-up attachment was provided. The operator had to also support the weight of the grain flowing through the conduit as the conduit was moved around the area to be cleaned of grain. Such equipment has the further very substantial disadvantage that the pick-up ends of such conduits have customarily been positioned in direction so that they are sucked down toward the floor. This requires the operator to expend the added energy to keep the pick-up ends or heads from being sucked into contact with the floor cutting off material flow. End rollers have been provided to try to keep such heads up off of the floor, but these rollers are of no effect when it becomes necessary or desirable to pick up material from a higher portion of a pile. The downward draft resulting from flow into such pick-up heads must still be resisted by the operator.
It is known to remove leaves from lawns and to clean factory aisles, sidewalks and the like with large vacuum cleaners. For example, U.S. Pat. No. 3,491,399 granted in January of 1970 of Dolan et al shows such a device having a pick-up arrangement supported on rollers to run at different fixed distances with respect to the ground. Where large light litter such as crumpled paper, for example, is encountered, Dolan provides means for opening a flap on the front of his pick-up arrangement, and raising the front of such arrangement farther off of the ground to accommodate such trash. Then, in order to get full and thorough pick-up from the ground, the flap is closed, and the pick-up arrangement is once again lowered into very close proximity to the ground. This is clearly shown in FIGS. 2 and 3 of the Dolan patent.
Perhaps the original idea of collecting dust and conveying it into a "dust collecting machine" is shown in the ancient patent to Agan, U.S. Pat. No. 862,369, granted in August of 1907, where a head is mounted on rollers very close to the floor, and a very narrow opening is provided to draw in air right off of the floor, holding the head tightly down against that surface.
The patent to Hyams, U.S. Pat. No. 4,366,594, granted in January of 1983, shows a vacuum-operated debris collector including a mobile frame and a collection receptacle and impeller unit assembly mounted on the frame. From FIG. 2 of that patent, it appears that the suction head 114 is to be guided for movement over the ground by a handle 116, and that the reduction of pressure in the head tends to pull the head directly into the ground. There is no provision for helping the operator handle this suction head other than by main force.
FIG. 5 of the Hyams patent discloses "a different form of section (sic) head which may be employed with the equipment." In the specification, column 4, beginning at line 37, it is pointed out that: "A relatively small suction head, such as that illustrated in FIG. 5 at 132, would provide a relatively concentrated vacuum for use in hard to clear places, where space limitations are severe." Such a "relatively small suction head" providing "relatively concentrated vacuum" would, indeed, pick up everything in its path, including, for example, not only low density particulate materials, but also sticks and stones, nails, and bolts, etc.
Another downwardly facing "surface cleaning tool" is shown in the patent to Duff, U.S. Pat. No. 2,850,757, granted in September of 1958. Like the other patents of the prior art cited herein, this downwardly facing structure would not allow sufficient space for the free flow of particulate materials into the pneumatic conveyor to be effective in the present context
Similarly, the design patent to Wiese et al, U.S. Pat. No. 277,517, granted in February of 1985, shows another downwardly facing hood design with rollers and wheels to support the pick-up apparatus in such a manner that it would not be effective in the present context.
The foregoing patents were cited in a search of the prior art. Applicant and those in privity with him are aware of no prior art closer than that discussed above and are aware of no prior art which anticipates the claims set out herein.